Peter out

Dear Word Detective: I have tried to research the origin of the phrase “peter out” — specifically, who was or what is “peter”? — but my sources seem to have petered out. Help. — Ken Young.

Well, there you go. Researching word origins is a lot like catching a cat so you can give it its medicine. The first day, no problem, it trusts you. But unless your cat is extremely thick, it’s going to recognize what it means when, the next day, you sidle casually into the room whistling something tuneless. Then you get to spend the next eight hours fruitlessly searching the entire house (“I know it’s January, but maybe you opened a window without realizing it.”). The trick is to stride confidently toward the front door, ignoring the cat, and then, at the last moment, fling a large salmon net over the critter. Similarly, the last thing you should do when wondering about an etymological puzzle is to look it in the eye and attempt to “do it yourself.” That way lies madness. Just send your question to me, preferably written in the memo space on a large check. (Just kidding. Sort of. Salmon nets aren’t cheap.)

So, who was or what is the “peter” in “peter out”? I’m not surprised that your search for an answer “petered out” (defined by the Oxford English Dictionary (OED) as “to run out, decrease, or fade; gradually to come to an end or cease to exist”), because the answer is far from clear.

It’s probably easiest to begin by eliminating some possibilities. “Peter out” is almost certainly not related to Saint Peter, one of the twelve Apostles of Jesus (even though he famously wavered in his support of Jesus), and does not appear to be drawn from the name of any other “Peter,” whether historical or fictional.

What we do know about “peter out” is that it was a US invention, and that it first appeared in print in the mid-1800s as mining slang, specifically describing a promising vein of ore (gold, silver, etc.) that did not live up to the miners’ hopes (“He discovered they [the lodes] had only a poor sickly trace of ore, which soon ‘petered out’,” 1877.) By the early 20th century, “peter out” was being used to describe nearly anything that, after a promising start, either failed to “pan out” (another 19th century mining term, from panning for gold nuggets in streams) or simply faded away (“Hurricane ‘Belle’ … petered out before reaching the Quoddy area,” 1976).

Given the original mining context, we have two possible explanations for the “peter” in “peter out.” One is what we call “saltpeter” here in the US, but is more properly known as “saltpetre,” aka potassium nitrate, a component of gunpowder. Blasting was a common practice in 19th century mining, and “peter” has been a slang verb since that time meaning “to use explosives” (“The Dolman boys are going to peter a pawnshop safe tonight,” 1962). So it’s possible that exploring a promising vein of ore with the wonder of dynamite and then finding that it leads nowhere gave us “peter out.”

Another possible source, which I think is more likely, is the French verb “péter,” meaning both “to explode” and “to break wind.” This “péter” gave us the English “petard,” a small bomb, as found in the phrase “to be hoist with his own petard,” meaning to be a victim of one’s own scheme. As English slang in the form “peter,” this “péter” was also used to mean “loaded dice” and as a verb meaning “to stop.” It seems possible that “peter” in either the “bomb” or “fart” sense may have given us “peter out” meaning “to stop” or “to prove meaningless.”